Here are some rules that even the most diehard drinkers should known when they cross the Atlantic.

* To get around the late-night drink drought, do what the Brits do: Start earlier, drink faster and when the bar-man rings his bell and calls “last orders,” down as many pints as you can.

* Hard-drinking New Yorkers who are used to tasting the alcohol in their vodka-and-tonics should order “a double.” Unlike cocktails made by free-pouring, Big Apple bartenders, British drinks are carefully measured out in singles and doubles. On the New York scale of alcohol content, a single hardly registers.

* Good news for those on a travel budget: Brits rarely tip. No barman will be sorry if you slip him an extra pound when he serves you a drink, but he won’t chase you out of the bar if you don’t.

* Friendly Americans like nothing better than to strike up a conversation while propping up the bar. Shy Brits do not. So don’t take it personally if you try to make small talk with a stranger and he looks at you as if you were an axe-murderer.

* If you’re out drinking with English pals, the tradition of every man for himself does not apply. Nothing is ruder than going up to the bar, getting yourself a drink and not offering to buy “a round.” The good thing is that everyone else buys rounds, too.

* In bar culture, obsession with soccer is sacred and passionate. If you overhear a conversation raging on about “football,” do not barge in with your opinion of the latest Jets line up. In fact, if you value your life, do not barge in at all.